Synthase
Encyclopedia
In biochemistry
, a synthase is an enzyme
that catalyses a synthesis
process.
Following the EC number
classification, they belong to the group of ligase
s, with lyase
s catalysing the reverse reaction.
Note that, originally, biochemical nomenclature distinguished synthetases and synthases. Under the original definition, synthases do not use energy from nucleoside triphosphates (such as ATP, GTP, CTP, TTP, and UTP), whereas synthetases do use nucleoside triphosphates. However, the Joint Commission on Biochemical Nomenclature (JCBN) dictates that 'synthase' can be used with any enzyme that catalyzes synthesis (whether or not it uses nucleoside triphosphates), whereas 'synthetase' is to be used synonymously with 'ligase'.
Biochemistry
Biochemistry, sometimes called biological chemistry, is the study of chemical processes in living organisms, including, but not limited to, living matter. Biochemistry governs all living organisms and living processes...
, a synthase is an enzyme
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...
that catalyses a synthesis
Biosynthesis
Biosynthesis is an enzyme-catalyzed process in cells of living organisms by which substrates are converted to more complex products. The biosynthesis process often consists of several enzymatic steps in which the product of one step is used as substrate in the following step...
process.
Following the EC number
EC number
The Enzyme Commission number is a numerical classification scheme for enzymes, based on the chemical reactions they catalyze....
classification, they belong to the group of ligase
Ligase
In biochemistry, ligase is an enzyme that can catalyse the joining of two large molecules by forming a new chemical bond, usually with accompanying hydrolysis of a small chemical group dependent to one of the larger molecules...
s, with lyase
Lyase
In biochemistry, a lyase is an enzyme that catalyzes the breaking of various chemical bonds by means other than hydrolysis and oxidation, often forming a new double bond or a new ring structure...
s catalysing the reverse reaction.
Note that, originally, biochemical nomenclature distinguished synthetases and synthases. Under the original definition, synthases do not use energy from nucleoside triphosphates (such as ATP, GTP, CTP, TTP, and UTP), whereas synthetases do use nucleoside triphosphates. However, the Joint Commission on Biochemical Nomenclature (JCBN) dictates that 'synthase' can be used with any enzyme that catalyzes synthesis (whether or not it uses nucleoside triphosphates), whereas 'synthetase' is to be used synonymously with 'ligase'.
Examples
- ATP synthaseATP synthaseright|thumb|300px|Molecular model of ATP synthase by X-ray diffraction methodATP synthase is an important enzyme that provides energy for the cell to use through the synthesis of adenosine triphosphate . ATP is the most commonly used "energy currency" of cells from most organisms...
- Citrate synthaseCitrate synthaseThe enzyme citrate synthase exists in nearly all living cells and stands as a pace-making enzyme in the first step of the Citric Acid Cycle . Citrate synthase is localized within eukaryotic cells in the mitochondrial matrix, but is encoded by nuclear DNA rather than mitochondrial...
- Tryptophan synthaseTryptophan synthaseTryptophan synthase or tryptophan synthetase is an enzyme that catalyzes the final two steps in the biosynthesis of tryptophan. It is commonly found in Eubacteria, Archaebacteria, Protista, Fungi, and Plantae. However, it is absent from animalia. It is typically found as an α2β2 tetramer...
- PseudouridinePseudouridinePseudouridine is the C-glycoside isomer of the nucleoside uridine, and it is the most prevalent of the over one hundred different modified nucleosides found in RNA. Ψ is found in all species and in many classes of RNA except mRNA...
synthase - Fatty acid synthaseFatty acid synthaseFatty acid synthase is an enzyme that in humans is encoded by the FASN gene.Fatty acid synthase is a multi-enzyme protein that catalyzes fatty acid synthesis...
- Cellulose synthase (UDP-forming)Cellulose synthase (UDP-forming)In enzymology, a cellulose synthase is an enzyme that catalyzes the chemical reactionThus, the two substrates of this enzyme are UDP-glucose and a chain of 1,4-beta-D-glucosyl residues, whereas its two products are UDP and an elongated chain of glucosyl residues...
- Cellulose synthase (GDP-forming)Cellulose synthase (GDP-forming)In enzymology, a cellulose synthase is an enzyme that catalyzes the chemical reactionThus, the two substrates of this enzyme are GDP-glucose and n, whereas its two products are GDP and n+1....